Safety discharge means



Nov. 8, 1966 s. T. WILLIAMS SAFETY DISCHARGE MEANS Filed Jan. 19, 1965 United States Patent 3,283,960 SAFETY DISCHARGE MEANS Selden T. Williams, Middlebury, Conn., assignor to Scovill Manufacturing Company, Waterbury, Conn., a corporation of Connecticut Filed Jan. 19, 1965, Ser. No. 426,529 3 Claims. (Cl. 222-397) This invention relates generally to safety discharge means for pressure fluid containers. It is intended especially for aerosol containers adapted to retain contents of various kinds under considerable pressure. Many of such materials when subjected to heat will develop pressures beyond the capacity of the container to resist, and which might produce an explosion. The pressure relief device will operate at a pre-determined pressure and completely release the contents so as to prevent any dangerous explosion.

An object of the invention is to provide a reliable saftey discharge device for aerosol containers which at the same time is economical to make. Pursuant to this objective, a relief outlet is provided by shearing away and reforming a small sect-ion of the container wall and covering the outlet thus made with a frangible membrane, such as a metal foil sealed to the inner surface surface of the container around the relief outlet.

Another object is to provide a bridge to protect the thin frangible membrane from being injured accidentally, or by a curious person. Pursuant to this objective, the material sheared from the container wall to provide the relief outlet is formed outwardly but remains connected to the wall portion from which it is sheared so as to form said bridge over the opening.

Still another object is to protect the user in the event that the safety discharge device operates to eject the contents of the container. To this end, the orifice or orifices through which the material is discharged after the foil is ruptured, are so arranged that the jets will be diverted and broken up by portions of the container rather than being dis-charged directly into the air.

Other objects and advantages will hereinafter more fully appear.

In the accompanying drawing, I have shown for purpose of illustration, one embodiment which the invention may assume in practice. In the drawing:

FIG. 1 is a central vertical section through the top of an aerosol container, incorporating my invention;

FIG. 2 is a detailed cross-section on line 22 of FIG.

FIG. 3 is a cross-section on line 3--3 of FIG. 2;

FIG. 4 is a fragmentary detail showing the safety discharge device in top plan view;

FIG. 5 is a view similar to FIG. 2, showing the condition after rupture of the foil; and

FIG. 6 is a view similar to FIG. 3, also showing the condition after rupture.

The aerosol container may be the common cylindrical sheet metal can 7 having .a sheet metal cover 8. 'The cover has a rolled rim 9 fitting over the rolled rim 10 of the sheet metal can. The cover 8 is off-set inwardly of the mouth of the container and has a central upstanding tubular neck 11. Any known type of valve 12 is suitably anchored in this neck 11 and is operated by a finger piece 13.

Although at least some of the purposes of the invention could be accomplished by locating the safety discharge device in any portion of the container wall, it is distinctly advantageous to utilize for this purpose, the horizontal annular wall portion 14 which forms the bottom of the toroidal-shaped well 15 between the depending wall portion 16 of the cap 8, and the neck 11.

The relief opening is formed by shearing a small section of the metal along shearing lines 17 and 18, best seen in FIG. 4, and the material thus sheared is pushed outwardly while remaining integral with the wall portion 14 at one or preferably both ends. This provides an impervious bridge 19 to overlie the relief opening while at the same time, leaving side outlets 20 and 21 which constitute orifices directed laterally one against the upstanding wall 16 of the cap and the other against the neck 11. Thus, when the container contents are discharged through the openings 20 and 21, the jets will impinge against the neck 11 .and wall 16 and will be broken up with less likelihood of injury to the use-r than if the material escaped directly into the air (see FIG. '6).

The relief valve is normally hermetically closed by a frangible membrane, preferably in the form of a piece of metal foil 22, sealed to the inner surface of the wall 14, completely around the relief outlet. This seal is :acc-omplished by suitable adhesive indicated at 23. That portion of the foil which would otherwise be exposed to damage is protected by the bridge 19.

It will be evident that the device is economical to manu facture. Before the cap 8 is applied to the can 7, the metal bridge 19 may be sheared out and the small metal foil applied to the opening opposite the bridge. The dimensions may vary, depending on the pressure at which it is desired to have the foil rupture; for example, I have found that with an opening of approximately .075 in width and a foil of .001 in thickness, the rupture will occur at approximately l bs/sq. in.

When rupture does occur as noted in FIGS. 5 and 6, the portion of the foil which is broken away will lodge against the bridge 19 and the contents will be discharged laterally through openings 20 and 21 against the vertical surfaces of the cap heretofore described.

What 1 claim is:

1. Safety discharge means for a pressure fluid container comprising a thin container wall portion having a small section sheared away and formed outwardly to provide an opening through the container wall with a laterally directed relief outlet adapted to discharge material in a direction generally parallel to said container wall portion, said outwardly formed section providing an impervious bridge over said opening, said bridge being integrally united to said container wall along part of the edges of said opening, and substantially co-extensive with said opening, and a frangible membrane covering said outlet and sealed to the inner surface of :said wall portion around said opening.

2. In an aerosol container, a sheet metal cap having an outwardly formed central neck, a manually operable discharge valve mounted in said neck, said cap having a laterally extending wall portion around said neck, a small section of said wall portion being sheared away and formed outwardly to provide an opening through the container wall with a laterally directed relief outlet from the container, said outwardly formed wall section constituting .an impervious bridge substantially co-extensive with said opening and which remains integrally united with said wall portion except along the lines of shear so that material discharged through said opening will be directed laterally in a direction generally parallel to said wall portion, and a fragible membrane covering said outlet and sea-led to the inner surface of said wall portion around said opening.

3. An aerosol container as defined in claim 2, wherein said cap is further provided with an outer upstanding wall spaced from and concentric with said neck to provide a toroidal-shaped Well with said laterally extending wall portion forming the bottom of the well, and wherein said small section is defined *by two parallel shear lines extending in a direction normal to a radial line from the central axis of said neck, whereby discharged material is directed laterally against said neck and said outer wall.

References Cited by the Examiner UNITED STATES PATENTS Willcox 22089 X Cooper 22089 Seaquist 222-397 Greene 220-89 Shallady et a1. -222- 397 Southworth 22044 X 10 RAPHAEL M. LUPO, Primary Examiner. 

1. SAFETY DISCHARGE MEANS FOR A PRESSURE FLUID CONTAINER COMPRISING A THIN CONTAINER WALL PORTION HAVING A SMALL SECTION SHEARED AWAY AND FORMED OUTWARDLY TO PROVIDE AN OPENING THROUGH THE CONTAINER WALL WITH THE LATERALLY DIRECTED RELIEF OUTLET ADAPTED TO DISCHARGE MATERIAL IN A DIRECTION GENERALLY PARALLEL TO SAID CONTAINER WALL PORTION, SAID OUTWARDLY FORMED SECTION PROVIDING AN IMPERVIOUS BRIDGE OVER SAID OPENING, SAID BRIDGE BEING INTEGRALLY UNITED TO SAID CONTAINER WALL ALONG PART OF THE EDGES OF SAID OPENING, AND SUBSTANTIALLY CO-EXTENSIVE WITH SAID OPENING, AND A FRANGIBLE MEMBRANE COVERING SAID OUTLET AND SEALED TO THE INNER SURFACE OF SAID WALL PORTION AROUND SAID OPENING. 